Methods for using polyol esters to control pests

ABSTRACT

Methods are disclosed for killing or knocking down pests selected from the group consisting of cockroaches, ants, bristletails, wasps, hornets, crickets, earwigs, centipedes, scorpions, sowbugs, pillbugs, and spiders. One sprays the pest directly with a solution that is at least 2.8% ester of a polyol (such as sucrose octanoate or sorbitol octanoate). The formulation is designed for use in kitchens, pantries and other areas of the home in which food items may be present. Spray bottle assemblies are also disclosed for delivering the material to the target pest in a desirable manner.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims priority based on U.S. provisional application60/551,289, which was filed on Mar. 8, 2004.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH/DEVELOPMENT

Not applicable

BACKGROUND OF THE INVENTION

The present invention relates to methods for controlling certain insectsand other pests by applying solutions of polyol esters, particularlysugar esters, directly to the pests.

A variety of pesticidal formulations are known for controlling insects,and other pests controlled by techniques similar to those used tocontrol insects, in various environments. However, for most of theseformulations the formulations contain one or more ingredients that havenot previously been recognized as safe for use in connection with foods.Hence, the usage directions for such products, and/or the governmentalapprovals for using such products, often contain undesirablerestrictions. Also the use of such pesticides is sometimes perceived bycertain consumers as undesirable (e.g. the organic foods movement).

Some pesticides with improved toxicity and/or degradabilitycharacteristics, such as alkyl glycosides, have been developed. See e.g.U.S. Pat. No. 4,888,325. However, they are not optimal for certain uses.

As described in U.S. Pat. No. 6,419,941 (the disclosure of which ishereby incorporated by reference as if fully set forth herein), the arthas also discovered a class of polyol esters. Some of these esters aresugar esters that naturally occur in certain plants. Others have beensynthesized, such as by using an ester manufacturing process like thosedescribed in U.S. Pat. No. 5,756,716. These syntheses typically involvedreacting an organic acid with a polyol (preferably a sugar type moietyin ring or linear form) in an esterification reaction, where the polyolcontains five to twelve carbons. The polyol ester which results may be amonoester, or may be a mix of monoesters with multiple esterifiedvariants. For purposes of the present invention polyols of sucrose,sorbitol, and xylitol are of greatest interest.

Certain sugar esters have previously been proposed to be used to sprayplants/mushrooms so as to control certain soft body/sensitive pests suchas psylla, sciarid flies, white flies, scales, hornworms, aphids andspider mites. For example, AVA Chemical Ventures (d/b/a/Avachem)commercially sells a 40% aqueous solution of sucrose octanoate for sprayin diluted form on various plants/mushrooms. In this regard, theysuggest diluting it and then spraying a 1.25% to 2.5% solution onmushrooms to control a sciarid fly infestation. Other Avachem literaturesuggests spraying plants with even lower concentrations of theformulation to control aphids and spider mites.

There have also been prior art suggestions to use such compounds (e.g.sucrose octanoate ester) to control Varroa mites infesting populationsof adult honey bees. These compounds were perceived as being safe to thedesirable commercial honey bee population, notwithstanding that it couldbe used to control such mites. Similarly, the USDA has publishedinformation on the use of sucrose octanoate which indicates that it is adesirable plant insecticide because it can control certain softbody/sensitive insects while not controlling certain hard body insectsthat are desirable (such as a lady beetle).

Hence, prior to the present invention, it was generally thought by theart that polyol esters like sucrose octanoate and sorbitol octanoatewere not effective pesticides against more resilient types of pests. Infact, the art thought that this selectivity made these compoundsparticularly desirable for certain purposes.

Thus, a need still exists for pesticidal formulations that can control avariety of resilient insects/pests in an environmentally acceptable way,and improved techniques for using such formulations.

BRIEF SUMMARY OF THE INVENTION

The invention provides a method of killing or knocking down a pestselected from the group consisting of cockroaches, ants, silverfish,firebrats, bristletails, wasps, hornets, crickets, earwigs, centipedes,scorpions, sowbugs, pillbugs and spiders, comprising spraying the pestwith a formulation comprising an ester of a polyol. In preferred formsthe ester is an ester of an organic acid with a five to twelve carbonpolyol, especially where the organic acid has between two and sixteencarbons. For example, the ester could be sucrose octanoate, sorbitoloctanoate, sorbitol decanoate, xylitol laurate, and sucrose octaacetate.The most preferred esters may be monoesters, or mixtures of monoesters,diesters and triesters.

Apart from the ester used, we have discovered that it is desirable todirectly apply the chemical to the pest, rather than merely applying thechemical to an environment (such as a plant leaf) where the pest mightlater be. Further, we have discovered that it is important that theanimal be contacted with a sufficient amount of the ester by directspraying (e.g. 0.1 gram or preferably 0.25 gram or more). This can beachieved by spraying the pest with a formulation having a relativelyhigh concentration of the ester (e.g. 2.8% or above) where the spray isa relatively concentrated spray. However, it can also be achieved evenwith lower concentrations (e.g. 0.5%) where multiple puffs of spray areapplied. Thus, a single puff of spray can be sufficient with a 2.8%concentration, whereas multiple puffs might be needed for sufficienttreatment at lower concentrations.

The ester is preferably delivered in an aqueous solution (e.g. 80% ormore water), and most preferably the solution has nothing in it besidesthe water and the ester. One way to achieve this would be to acquirefrom Avachem Chemical Ventures, LLC of Portsmouth, N.H. their 40%aqueous solution of sucrose octanoate (a mixture of mono, di and triesters), and then dilute it down to a 5% concentration using distilledwater, and then place the liquid in a spray bottle such as the Calmar15508P118 bottle set on a crude spray setting (see also U.S. patent Re.33,235). One then could spray a pest, such as a cockroach, with thespray from a distance of about 0.1 to 1 meter.

Alternatively, for solubility or other reasons, one may decide to useother solvents besides water for some esters. For example, one couldobtain sucrose octanoate from Applied Power Concepts, Inc. of Orange,Calif. They dissolve their mono, di and tri esters in n-butanol. If onestarts with a 90% solution in n-butanol water can dilute the solution tothe preferred range of concentration.

If an aerosol form is desired, one could add a hydrocarbon propellant(e.g. isobutane/propane mix), plus a small amount of surfactant tocreate an emulsion or microemulsion, plus corrosion inhibitors,fragrances, or other known aerosol insecticide additives.

It is particularly preferred that the formulation be sprayed from a handpump spray bottle where the bottle can deliver at least 95% of its spraywhich reaches a surface which is one meter from the sprayer, within 0.5meter of a selected target point on that surface. This maximizes theamount of spray contacting the target insect.

In another aspect the invention provides a spray bottle assembly fordelivering insecticide. It has an internal cavity containing the aboveformulation. There is also a trigger-activated pump for pumping theformulation from the cavity to an outlet. Manual activation of thetrigger can cause the assembly to spray a surface that is one meter fromthe outlet such that at least 95% of the spray which reaches thatsurface will contact the surface within 0.5 meter of a selected point onthat surface.

As will be appreciated from the following, the present invention cancause quick knock down of, and ultimately kill, a variety of hardbody/more resilient pests common in the home. The control can beachieved with just a water solution of the ester being sprayed on theinsect. Hence, the cost of the formulation can be kept reasonable,formulating the formulation is easy, and the formulations will be morewidely acceptable with respect to environmental concerns.

The preferred pests to be controlled are crawling insects such ascockroaches and ants. However, the formulations can also be used onnests of flying insects such as wasps.

The foregoing and other advantages of the invention will become apparentfrom the following description. In the following description referenceis made to the accompanying drawing which forms a part thereof, and inwhich there is shown by way of illustration a preferred embodiment ofthe invention. This embodiment does not represent the full scope of theinvention. Reference should therefore be made to the claims herein forinterpreting the scope of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a sectional/schematic view of a spray bottle capable ofdelivering the formulations of the present invention in a desirablemanner.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A. Spray Bottles

A wide variety of known pump type spray bottles can be used to deliverthe formulations. See e.g. U.S. patent Re. 33,235. The most preferredspray bottles are those that have nozzles which direct the spray in amore focused pattern (as distinguished from a widespread fine spray).

FIG. 1 shows an example of one type of spray bottle that would besuitable for use with the present invention. There is a pump assembly 1having an inlet 2 and an outlet 3. A dip tube 4 extends downward therefrom.

A cap 5 engages the usual bottle 6 in threaded fashion. Prior toassembling the cap 5 to the bottle 6 the bottle is substantially filledwith formulation 7 of the present invention.

As is conventional, the pump assembly 1 has a cylinder 8 having an endwall 9 containing an inlet 11. The outlet port 12 extends to a nozzlesection 13. The assembly may be provided with the usual shroud 14 havingdecorative contoured walls 15.

The outlet portion 18 of the nozzle is configured to provide a directedfocused spray. There is also a trigger 19.

In operation, and as is well understood in the art, compression of thetrigger 19 pushes the pump assembly components, causing spray to beejected out the outlet portion 18. The return of the trigger to its restposition permits the chemical 7 to be sucked into the pump chamber.

The novelty of FIG. 1 relates to the chemistry of the chemical 7 and theselection of a nozzle outlet portion 18 which provides a focused sprayin connection therewith.

B. Formulations.

In our experiments we created aqueous solutions of sucrose octanoate andsorbitol octanoate by diluting the more concentrated formulationsprovided by the aforesaid manufacturers. We created variedconcentrations ranging from 0.05% through 10%.

C. Testing.

We tested our formulations by spraying them on cockroaches, ants,crickets, silverfish, wasps, bristletails, hornets, centipedes, earwigs,spiders and sowbugs. For example, we found our formulations capable ofcontrolling all these species given direct application of a concentratedspray of the formulation. We found that when spraying about three gramsof the formulation containing sucrose octanoate we had essentially nokill at 24 hours for German cockroaches at 0.1% concentration, about 80%kill at 24 hours for German cockroaches at 1% concentration, and 100%kill at 5% concentration.

In other experiments, the average time to achieve knock down of suchcockroaches was over a minute at concentrations of only 1%. It was about19 seconds for a 2% solution, and then at about 16 seconds forconcentrations between 3 and 5%. The optimal concentration forapplication appears to be about 2.8% or above.

Using 5% concentrations, average knock down times of 40 seconds or belowwere achieved for various other species as well (e.g. ants, crickets,silverfish, wasps, bristletails, and hornets). Hence, the invention iswidely applicable to insects and other pests controllable by techniquescommonly used to control insects (e.g. centipedes).

Hence, we have discovered that by applying these chemicals directly toeven hard body/resistant type pests, in sufficient concentrations of theester, desirable control can be achieved (both quick knock down andeffective kill). We believe that for a typical pest of the specifiedtypes a desirable dose to contact the pest is at least 0.1 gram of theester.

The above description has been that of preferred embodiments of thepresent invention. It will occur to those that practice the art,however, that still other modifications may be made without departingfrom the spirit and scope of the invention. For example, the solutionsneed not be entirely aqueous solutions. Mixes of alcohols, hydrocarbonsand water should also be useful. Further, a wide variety of other sugaresters should also have similar results.

INDUSTRIAL APPLICABILITY

The present invention provides methods for controlling a variety ofinsects and other pests using polyol ester compounds, as well as spraybottles suitable to deliver those compounds in an effective manner.

1. A method of killing or knocking down a pest selected from the groupconsisting of cockroaches, ants, silverfish, firebrats, bristletails,wasps, hornets, crickets, earwigs, centipedes, scorpions, sowbugs,pillbugs, and spiders, comprising: spraying the pest with a formulationcomprising an ester of a polyol; whereby the pest is killed or knockeddown.
 2. The method of claim 1, wherein the pest is selected from thegroup consisting of cockroaches and ants.
 3. The method of claim 2,wherein the pest is a cockroach.
 4. The method of claim 1, wherein theester is an ester of an organic acid with a five to twelve carbonpolyol.
 5. The method of claim 4, wherein the organic acid has betweentwo and sixteen carbons.
 6. The method of claim 5, wherein the ester isselected from the group consisting of sucrose octanoate and sorbitoloctanoate.
 7. The method of claim 1, wherein the formulation comprisesat least 0.5% of the ester by weight.
 8. The method of claim 7, whereinthe formulation comprises at least 2.8% of the ester by weight.
 9. Themethod of claim 1, wherein the formulation comprises at least 50% water.10. The method of claim 9, wherein the formulation comprises at least80% water.
 11. The method of claim 1, wherein the pest is contacted withat least 0.1 gram of the ester.
 12. The method of claim 1, wherein theformulation is sprayed from a spray bottle having an outlet capable ofdelivering at least 95% of its spray which reaches a surface which isone meter from the outlet, within 0.5 meter of a selected point on thatsurface.
 13. A spray bottle assembly for delivering insecticide,comprising: an internal cavity containing a formulation comprising anester of a polyol; and a trigger-activated pump for pumping theformulation from the cavity to an outlet; whereby manual activation ofthe trigger can cause the assembly to spray a surface that is one meterfrom the outlet such that at least 95% of the spray which reaches thatsurface will contact the surface within 0.5 meter of a selected point onthat surface.